


The Professor's Son

by EquinoxSolstice



Series: The Professor's Family [2]
Category: K-pop, 방탄소년단 | Bangtan Boys | BTS
Genre: Alternate Universe - College/University, Established Relationship, Falling In Love, Families of Choice, Family, First Date, Fluff, Genius!Taehyung, HousehusbandMothering!Jin, Jungkook falls in love, Kim Siblings Taehyung and Namjoon, M/M, Meeting the Parents!AU, Professor!Namjoon, Slice of Life, Taehyung is a suave mf, Taehyung loves Math, competitions, jungkook is a shy bun, married!namjin
Language: English
Status: Completed
Published: 2016-10-11
Updated: 2016-10-11
Packaged: 2018-08-21 21:31:11
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 7,342
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8261062
Author URL: https://archiveofourown.org/users/EquinoxSolstice/pseuds/EquinoxSolstice
Summary: Math was often misunderstood, Taehyung said, on one of their dates along the Han River. People were always so afraid of it and refused to know more about it, dismissed it as something hard and unreachable and it made Taehyung upset. If people only tried to understand, he insisted, if only people approached it with an open mind and didn’t give up, then maybe a lot more people would love Math and would want to learn about it like he did.
Jungkook didn’t understand at first, but after knowing Taehyung, he now did.
Before he realized what was happening, thinking about Taehyung made his heart turn, dance a kind of waltz, then suddenly fell. 
Before he knew it, Jungkook was totally, completely in love with him.
The sequel to The Professor's Wife.





	

_Name: Jeon Jungkook_

_Age: 19_

_Occupation and Workplace: Freshman Engineering Student, Seoul National University_

_Status…_

Jungkook looked to his side the moment he heard the bell beside the café door tinkle, signaling another customer coming in. He gave a start at the newcomer, who immediately saw him and made his way to the table.

…  _Possibly going to be involved with Kim Taehyung._

_Hopefully._

"Jungkookie!" The older greeted his date, smiling, as he walked quickly walked towards their table and sat on the other side of the small booth that was more isolated than most. The café they went to was famous for being a dating spot among university students, and the atmosphere was created to cater to that: private, intimate, secretive. Taehyung was wearing the most adorably mismatched clothes Jungkook had ever seen, baggy pants with sandals (were those _crocs_?), a sweater ripped at the collarbone, under a large hoodie. His backpack was almost bursting, various odds and ends poking out in a sort-of ordered chaos. His safety goggles were still flopping around his neck, unnoticed by the older as he looked around for Jungkook.

If someone told Jungkook that this person was actually a goddamn _rocket scientist_ , he would have thought they were joking. But appearances were deceiving, and geniuses didn’t exactly follow societal conventions.

"Sorry I was late; I didn't expect that the flight experiment would take longer than usual. And it was a trial and error thing, so we had to do it multiple times." Taehyung said apologetically, sliding beside him in the booth and smiling, visibly enjoying the bright blush that spread on the younger teen's face. "Did you wait long?"

"No, I just got here." It really surprised his friends to find out that he had a… date that day. They had demanded the name and description of the person so they could do the inquisition on him, but Jungkook wasn't that comfortable yet to reveal that it was his math professor's 'son' whom he was dating. And that he was interested in males in the first place.

"Oh, so you have lab today?" He asked curiously, but also with a bit of worry, since the other teen looked absolutely exhausted. "If you want, we could cancel and do this another day, if you're tired."

"No, it's fine, Jungkook. Besides, I was the one who invited you, and it would be rude to cancel it when you waited for me. By the way, can I call you Kookie?" Chocolate brown orbs looked warm as they stared back at him and once again Jungkook had to stop the redness that was spreading all over his face and down his neck. He was sure he looked sunburned right now. My god, he thought with some desperation and a hint of fondness that had his mind spinning and heart thumping. "Anyway, thanks for… you know, accepting. I really appreciate it." Taehyung continued sincerely, and Jungkook’s heart stopped for a moment, before frantically speeding up into a velocity he didn't know his heart could reach.

Jungkook only knew this person for over a day, but why did Kim Taehyung have to be so adorably… sweet?

Kim Taehyung was his… well, for a lack of better word, date that afternoon, having been initially interested in him when they first met yesterday in Algebra class in which they both shared. The older student had immediately asked the other out for coffee the moment class was over, and Jungkook couldn’t find it in himself to refuse the invitation. Kim Taehyung was cute, and Jungkook was far too curious for his own good.

And so they both agreed to meet in the café the day after when classes were over, the former running a bit late, and the latter already half-hyperventilating, slowly turning crazy with waiting.

"I-It's all right. It's nothing, really. You can call me Kookie." He managed to murmur back, suddenly finding his fingers to be the most interesting thing he had ever seen, looking down at them and observing each nail with exaggerated interest. He honestly didn't know what to do. It was his first date, and with a guy too to boot. He didn't know anything about relationships or anything of that sort, he honestly thought that nobody would become interested in him.

Thankfully the arrival of the waiter broke what would've been the start of an awkward silence. They ordered, and Jungkook noticed, with a small glance to his side, that Taehyung ordered an extra dash of cinnamon in his caramel macchiato.

So he liked his coffee strong. Spicy, dark, and intense. Somehow, the order didn't surprise Jungkook, who ordered a mocha frappuccino and a slice of dark chocolate cake. Kim Taehyung certainly had the look of intensity on his face at times, as Jungkook watched him interact with the waiter through the corner of his eye. Looking at him reminded Jungkook once again of their math professor. He would recognize those brown colored orbs anywhere.

"Kookie," Taehyung started to ask, and the Jungkook student found himself sucked back into a conversation. He raised his eyes to meet caramel brown, and was surprised to find he didn't want to look away. Those pools of melted chocolate looked at him with such bright curiosity and attentiveness, as if the other could stare at him for hours if given the chance to. Taehyung leaned his face on his palm, an elbow propped on the table, smiling at him in a manner that was both charming and engaging at the same time.

Slightly dazed, Jungkook stared back, face catching aflame again.

"U-Um… I couldn't help but notice, but… are you related to Professor Kim in some way?" Jungkook blurted out the first thing that came to mind, and internally slapped himself when the older teen blinked in surprise, obviously not expecting that question. He was reasonably certain that Taehyung and the math professor were related, not just sure on how closely related they were. Genius ran in the family, and while he wasn’t belitting Kim Seokjin’s intelligence _at all_ (his respect for the man was so deep and real he wouldn’t even dare), it just… made more sense, somehow. Taehyung couldn't possibly be the older man's son since they only had a half a decade age gap. "I-I just can't help but see that you two interact somewhat familiarly with each other." He added hurriedly, if the other didn't want to answer, "And… you share the same last name? S-so sorry if I j-jumped to conclusions…" He looked down again, red-faced, and it was only the sound of laughter coming from his seatmate that had him looking up and blinking.

"Ah, no, that's not it," Taehyung answered after catching his breath, shaking his head and looking thoughtful. "Professor Kim and I are related, though most people assume that because we have the same last name, not because we talk comfortably with each other.” He gave a crooked smile. "People rarely see that I have a closer relationship with Professor Kim. I’m in a different department and it’s not common knowledge, so most people haven't caught on yet. Kim is a common last name, after all." Taehyung gave another short laugh, sounding so carefree, that Jungkook easily understood where that idea came from. It was actually hard to believe that someone as good-natured and outgoing as Taehyung would have a more reserved, thoughtful relative like Professor Kim.

But, even then, it was already obvious to Jungkook that the older and the professor had a blood connection. "He's actually my older half-brother." Taehyung explained casually, and paused as the waiter arrived, bearing their food.

Jungkook took a sip of his drink, relishing in the refreshing flavor of mocha and the mild taste of coffee. Ah, iced frappes really were the best. He placed the plastic cup back on the table, smiling a little and a little more relaxed now. Taehyung was surprisingly easy to get along with, and had an aura that put people completely at ease in his presence. "Ah, I see." He wrapped his hands around his frappe, now much more confident in continuing conversation.

"I was surprised though, that you thought that we were related because we’re familiar with each other. You're really observant, Jungkook." Taehyung said, looking at him again with that interested expression on his face, and the Jungkook managed not to blush too much this time.

"N-Not really, I thought it was obvious to everyone else." Was he watching Taehyung  _that_  closely? Not really wanting to answer his own question, Jungkook looked at him instead. "So the University allowed you in Professor Kim’s class even though you're a relative of his?" He asked curiously. The University had strict policies on this one, not wanting special treatment to students who had family members on their faculty and staff.

"Well, Namjoon-hyung isn’t my full brother. He’s trusted enough in his department to treat me as one of his students, and I’m in a different department, so he has no direct hold over me. Besides, the classes I’m taking with him are for general education courses, not majors." Taehyung gulped down his own drink, and the Jungkook had to stop himself from staring, shaking his head quickly and returning back to the conversation. "As long as he doesn't teach me the advanced lessons at home, and I'm doing my own work, it's all right with them."

"You live with him?" Jungkook already knew this, but felt the need to ask, since it would be awkward if the other would ask on how he knew that. He definitely didn't want to come off as a stalker. "What about your parents?"

"Hmm, yeah. I live with him and his partner." Jungkook noted the easiness and comfort Taehyung mentioned the professor and his spouse, and figured that he must've been living with them long enough to be open to the thought of his older brother being in a relationship with another man. Taehyung leaned back, drumming his fingers continuously on the table as he started his tale. "Our parents were divorced when Joon-hyung was really little… three, I think? Our dad moved to Daegu, married my mom, had me. But we lived in the countryside, and my parents wanted me to have a good education, so they sent me to Seoul to study here. I was… starting middle school? I think. Namjoon-hyung’s parents work overseas, they move from one country to another every few years, and originally they wanted to bring him with them. But our Grandfather thought that moving frequently would interfere with hyung’s 'personal growth' and convinced them that he should just stay back in Korea. At that time, I was already looking into moving to Seoul, and things just worked out from there." Taehyung smiled. "I really don't mind much though. Hyung’s parents come home every year for Christmas, and they’re really great parents to hyung, and to me. It’s like having a second family." His tone turned nostalgic, maintaining eye contact as he continued.

"So I stayed with Namjoon-hyung for half of my life. When I was in high school, he moved to Daejeon with his partner because of university, and I moved with him." Taehyung grinned in affectionate remembrance. "Namjoon-hyung’s the only older brother I have in my life, even though he was still in KAIST at that time. He was always there for me when I was growing up." A soft, affectionate look crossed his features, and Jungkook found he couldn't look away, completely captivated.

_God, he's so handsome._

"He and Jin-hyung were the closest things to parents that I've had." Taehyung finished, taking another glance at him and giving a quick, but genuine smile. "But you might find my family a little unusual, if you get to know them."

You have no idea, Jungkook thought, looking away and blushing, taking a sip of his drink. Taehyung’s explanation filled in a lot of blanks for him, and explained the pictures he had seen in their house. "I see.” And because Taehyung was so open, so willing to talk about his complicated family, that Jungkook felt it was okay to tell his own story. That Taehyung wouldn’t judge.

“My family's… not as close as yours." He said, lightly, and he explained his own situation. That his father got his mother pregnant at a young age, and they live together just for his sake, but it was clear that they didn't love each other, and argued incessantly in an almost daily basis. Taehyung listened intently with quiet understanding, not saying a word, only nodding along. Jungkook never noticed how _easy_ it was to talk to him about his family life, to divulge secrets that not even his closest friends knew. He already trusted Kim Taehyung this much, not even knowing him for a full day, but instead of being scared at the idea he only felt relief and security that he could finally talk to someone about it.

"… I would say that I'm sorry, but I know that you wouldn't like it." Taehyung finally said after a long while. While they were talking their food and drinks slowly dwindled down, and they've actually moved closer, shoulders almost brushing against each other, talking in low, hushed whispers. "But I'm really glad that you shared your story with me. Thank you, Kookie." He said sincerely, and the younger's heart stuttered in his chest.

He seemed so mature now, and Jungkook wondered how he could go from being all smiles to complete seriousness in an instant. But, at that moment, he could definitely see that the older was definitely Professor Kim’s younger brother.

"I-it's all right. I should be thanking you for listening to me. I must be a trouble." He was beyond embarrassed now, shifting his hold on his cup shyly. He couldn't look at Taehyung’s face now, knowing that he would look at Jungkook again with that… intense expression on his face.

"No, I really want to learn all about you, Jungkook." Taehyung said it so earnestly, sliding his hand to cover his. It made the Jungkook look up, breath hitching when their eyes met. "So you could never be a trouble for me."

… How was he going to answer to  _that_? His fingers trembled under Taehyung’s hold, and he knew that his face and neck were blushing riper than a tomato. God, he was so charming that Jungkook was slowly forgetting how to breathe.

"May I see you again?" Taehyung asked softly, giving his hand a gentle squeeze. "Kookie."

And he could only nod shyly; suddenly remembering to inhale oxygen again when Taehyung immediately brightened up and gave him a genuine, happy smile.

* * *

   


They'd been going on a few dates soon after that, and slowly but surely Jungkook was getting to know his… lover? Boyfriend? How to qualify? He knew that Taehyung was very passionate about astronomy, math, and hiphop, he played saxophone when he was younger, and liked unique things. Hiphop was something he inherited from his older brother initially, and the former coming in later after the considerable influence of his brother’s spouse. And though charming, friendly, and initially good-natured, the older was also very absent-minded, quirky, and just plain _strange_. It took some patience and understanding to keep up with him, to know what he was thinking, and it took some time for Jungkook to understand and accept his personality completely.

Taehyung wanted to pursue astronautical engineering post-graduate studies, and he wanted to be an astronaut and work in NASA. The reason why he liked Math, he confided in Jungkook, was because he understood it, it was a language he understood and could do, and he was good at it. He was a part of the academic decathlon team, more specifically, in the math section, and competed nationally and abroad.

(Math was often misunderstood, he said on one of their dates along the Han River. People were always so afraid of it and refused to know more about it, dismissed it as something hard and unreachable and it made Taehyung upset. If people only tried to understand, he insisted, if only people approached it with an open mind and didn’t give up, then maybe a lot more people would love Math and would want to learn about it like he did.

Jungkook didn’t understand at first, but after knowing Taehyung, he now did.)  

When Taehyung eventually competed, Jungkook made it a point to go to his matches to watch and cheer for him, despite Taehyung’s insistence that it was completely okay and he should concentrate on other things instead. Decathlons were honestly boring and quiet and the complete opposite of a sports match, but the intensity of the atmosphere, the tension as each group started to write their answers down on their boards were the same. Jungkook hardly understood what Taehyung was doing, despite leaning about it in class, but every time their team scored a point, Jungkook clapped as hard as he could, watched Taehyung as his was mobbed by his teammates for their win.

Originally he had tried solving an equation once, just for the experience, but then he found out that he didn't have a single, intelligent neuron in his brain. Taehyung had laughed and showed him how to solve it, their fingers tangled together as he helped Jungkook write the values on the whiteboard. He was really amazed to see his boyfriend play against his opponent, bright and funny outside the benches, sharp and ruthless inside them. He was a great competitor, a true mathematician, and Jungkook could easily see him figure out a new number sequence or equation and win a Nobel for it.

Jungkook didn't know what it felt like to fall in love. But one day, before he realized what was happening, thinking about the older made his heart turn, dance a kind of waltz, then suddenly fell.

It scared him to realize it at first; truthfully, Jungkook had never fallen in love before. Bouts of denial and insecurity soon followed, and with his lower than average self-esteem, it was quite hard for Jungkook to accept the fact that a thoughtful, completely wonderful person like Kim Taehyung would actually take an interest in him. And Taehyung would always go to great lengths to assure and comfort him, always taking him out on dates, surprising him with small gifts every once in a while, and being generally an all-around sweetheart, one that never failed to induce mini cardiac arrests every time he would do so.

All in all Kim Taehyung was a fine specimen of a man: funny, witty, kind, and before he knew it, Jungkook was totally, completely in love with him.

* * *

Kim Namjoon once again noticed the contemplative, almost searching look his spouse was giving his younger brother. For the past few weeks, Taehyung went through a quite a change in personality, though subtle and not that noticeable at first glance. The teen seemed more cheerful now, happier, and a lot more absentminded. At times they would see him stare off into space with a dreamy expression on his face, other times locking himself inside his room and coming out while Yanghwa Bridge played on speaker, and being more enthusiastic in general. Taehyung also went out of the house more frequently than usual outside of the normal, and would come home with a certain happy glow that the man knew all too well.  


In other words, the signs were blaring out as clear as day, and the man wasn't sure if it was a good thing.

His younger brother was in love.

A Kim, as a general rule, would only fall in love once in their lives. It happened to his ancestors, to his grandfather, his father and to him. He was fortunate enough to have that love reciprocated, unlike his other relatives who had loved and lost. Of course, they had moved on and found another, but the pains of their first love never left, and they were never truly happy.

And Taehyung was on his way to that crossroad.

"Jin…" He started off with an unsure tone, his gaze also following the younger man. Suddenly he felt so old, even though by all means he shouldn't feel that way. He was only twenty-five, and yet why did it feel as if he was watching his son preparing to leave home to start a new life without them?

"Oh, Taehyung will be fine." His beautiful spouse waved a hand at his unasked question, looking both happy and amused for their adopted pseudo-son, who had asked for permission to go out again, and was running around the house getting ready, not realizing that his 'parents' were observing his every move. "I'm not going to interfere. I do wonder who caught his attention though." He mused pensively, sounding nostalgic and a little sad.

Was this how to felt to see your own child spreading his wings and finally leaving his nest? Though they had a relatively small age gap, they already considered Taehyung as their own son. When they initially moved to Daejeon for University it was decided that Taehyung would live with them as well. Jin didn't mind, he had always doted upon the younger Kim, and he knew that his lover-turned-husband was also fond of his younger brother, though he didn't show it often.

The implication of them being a complete family wasn't lost on Namjoon. Even though it was hard to take care of an thirteen year old boy while juggling school work and part-time jobs (they had both wanted to be independent, and only agreed to receive allowance for Taehyung’s education), both of them felt that the hardship was worth it. They watched him grow, mature into the young man that he was now, always there for them when he smiled, cried, cheered for him when he played, gave him guidance and advice when he needed it.

But it wasn't always sunshine and rainbows. Both of them knew very well that some people avoided Taehyung simply because he was being raised by two men. Though not as observant as his lover, he would see how some people's warm gaze would instantly cool the moment Taehyung would jokingly introduce them as his 'parents'. Namjoon didn't know how many times Taehyung came home bruised and beaten, bullied constantly for his unconventional family, to the point that Namjoon regretted ever agreeing to be Taehyung’s guardian.

Blessedly, Taehyung seemed to take it all in stride, showing a maturity at one time when they were treating his wounds. He explained that people were often scared of things that they didn't know, and that he shouldn't hate them, because they simply didn't understand what was going on. Taehyung didn't blame them at all for what was happening to him, though it was partly their fault for not conforming to what society demanded of them. Jin had cried then, fiercely holding the boy close, promising him that they would always protect him no matter what, and Namjoon backed him up wholeheartedly.

Namjoon fell silent, wondering if he should tell Jin that he had an idea on who Taehyung was enamored with. No doubt his spouse would be pleased if he told him that Taehyung was spending a lot of his time with Jungkook, the student both of them had taken a liking to. They sat together during his classes now, and at times he would see them walking together, talking closely. Namjoon would be the last person to question other people's preferences, and even as early as now he already approved of his younger brother’s choice.

"Namjoon-hyung! Jin-hyung!" Taehyung burst into the room, startling the two men out of their private conversation. "How do I look?" He asked breathlessly.

Both exchanged glances, taking a quick, apprising look at the teen's attire. Taehyung was the type of person to dress up for the sake of comfort, and it surprised them a little the he was dressed up a little, a light-colored shirt underneath a collared, button up, skinny jeans, and a pair of Converse high-tops, and a leather jacket. He also wore some accessories, a silver-colored necklace, a thick, black, band on his wrist, and—was that a stud _earring_?—glinting on the lobe of one ear.

Jin managed a small sigh before standing up, approaching the younger man. "You look very handsome, TaeTae." He chuckled, smoothing down the popped up collar, carefully folding it down properly. Taehyung was as tall as him now, Jin thought wistfully. "Will you be gone long?" He asked, stepping back and beaming at the less unkempt look. "Now you look so much better."

Taehyung beamed. "Thanks Jin-hyung. I won't be out too late." He ruffled his hair slightly, lightly blushing. "Um…" He looked away, as if trying to find the words to express what he wanted to say afterwards.

"Will we be able to meet this person?" Jin interrupted gently; smiling at the other’s stunned expression. Namjoon merely looked up, waiting to see his brother’s reaction.

Taehyung blinked in surprise, not expecting the question at all. But then again, Jin-hyung and his older brother was the one who raised him for most of his life, so of course they would see the difference in him.

"… Yeah. I really, really like them, hyung." Taehyung admitted. "And I think you'll like them too." He added earnestly, making eye contact with his brother and felt relieved to see that the man gave a small nod of agreement.

"Is that so?" Jin smiled gently and hugged Taehyung briefly. "Have fun, all right?"

"Don't be out too late." Namjoon added from the couch, glancing up from the stack of papers he had to grade over the weekend. "Text what time you're going home."

"Yeah!" Another hug, a quick grab for a messenger bag, and Taehyung was out the door. "I'm going!"

"Take care!" Jin called after him, and they waited for the sound of the door slamming shut before letting silence reign over their house. Jin couldn't help the sad little exhale of air though, staring at the front door a little longer than usual. Why did they have to grow up so fast?

Namjoon, sensing the mood of his spouse, stood up and wrapped his arms around him, cradling him to his chest. He too, gave a small sigh, pressing his cheek against the soft, brown hair. "He's going to be fine, Jin."

"… I know." The other placed a hand on his arm, and Jin turned around, looking up at his husband, suddenly aware of the situation. The two of them. Alone in the house. Possibly for hours. And it hadn't happened for a long time now. Hm. Perhaps this might not be so bad after all. "Namjoon." He drawled out, giving a little, mischievous smile, arms curving around his neck and pulling him closer. "When was the last time we had the house to ourselves?"

"What?" The other man's brows furrowed slightly, considering the question. "The last time…?"

Jin chuckled lowly, walking backwards and pulling the other man with him until his back hit the front door. Work could be done later, time was of the essence. He definitely wasn't going to let this chance slip by. "I'll let you choose, babe." His hands travelled down Namjoon’s chest languidly, intently, with a purpose. He glanced up, and was pleased to see that his eyes darkened slightly, the other man pressing him fully against the door. His hands stopped just at the edges of the shirt where it was tucked into his sweatpants. Jin’s tone was light, and completely conversational.

"The wall or the dining table? Which one do you prefer?"

Namjoon cracked a small smirk, his own hands moving to hold a trim waist as he dipped his head down. "What about both?" He murmured before kissing his spouse deeply, swallowing the soft moan as hands quickly got busy and the rest of the world was completely forgotten apart from each other.

* * *

It was half a year into their strengthening relationship that the decathlon season started, the yearly Inter-University Tournament, and the finals were coming up this weekend. Korea University was one of the finalists, and once again Jungkook was on the lower bleachers, patiently waiting for the stands to fill up. They never did, but there were better seats than others, and he wanted the best one possible.  


Thank god he didn't have classes on the weekend, Jungkook thought, sitting down in the middle and scanning the ground below for any sign of the other teen. In the corner he saw Taehyung huddling with his teammates around, eventually spying a familiar blond mop standing out, somewhat taller than rest. Jungkook gave a start. What was Professor Kim doing there? It was the professor, he was gathering the team, giving them some final instructions.

Then he remembered Taehyung saying that their coach was sick today, and someone from the Math department was going to sub-coach for their competition today.

And it turned out to be Professor Kim.

Jungkook saw Professor Kim outside the classroom on occasion, passing by him in the always, giving a nod in acknowledgement whenever Jungkook would greet him. Their teacher-student relationship had changed quite a bit, somewhat more easy-going now, the clear line between them blurring just a bit.

"Jungkookie?" A familiar voice sounded at his side and he turned his head, visibly brightening up at the sight of the older man smiling and waving a hand in greeting.

"Jin-hyung! It's been a long time!" He shifted to the side, bowing, letting the man sit beside him. Jin gave the younger teen a brief, tight hug, making him flush pink, but fiercely returned the hug all the same. His professor's spouse looked as pretty as ever, hair gelled back this time, a soft rose pink, showing his forehead. He was wearing loose, comfortable clothes, a light pink sweater, jeans, sneakers, a satchel bag on his broad shoulder. The silver ring identical to the professor's was completely visible now, nestled on a thin, left ring finger.

"How are you, Jungkook?" Jin greeted him warmly, sitting beside him and ruffling his hair. Jungkook decided to change his hair color, a lighter shade of brown, down and pressed against his forehead.

"I'm fine, thank you. What about you, hyung? What are you doing here?" What a sight they made, Jungkook internally sighed as he chatted up the man. He was reasonably sure that a lot of people were staring at them, mainly because he knew Jin was such an eye-catcher, with his hair and broad stature. Jin also decided to forego his glasses in favor of contacts, making him look almost too perfect.

"Oh, I decided to surprise my favorite boys by watching their game today." Jin answered, chuckling. "I got off early from work today, and I figured that I spend my free time here instead of waiting at home alone. Ah, that reminds me," his face turned to the younger thoughtfully, "You haven't met Taehyung, have you? If I remember correctly, he's also in Namjoon’s Algebra class."

"A-Ah, that's…" Jungkook couldn't possibly tell the older man that he had known his brother-in-law for quite some time now, and they knew each other quite well, in fact. His thoughts turned to surprise, then horror, when he realized that he was now technically talking to his boyfriend's  _parent_. "I know him, he's my seatmate." Well, it wasn't really a lie; ever since they met Taehyung made it a point to sit beside him every lesson.

Jin looked undeniably pleased at that. "It really is a small world, after all." He beamed, looking down at the stage, just in time to see Taehyung’s team disperse, their team huddle finished. Jungkook knew Taehyung was playing Team Captain that day, and prayed that the team would pull through and win. He saw them going up the platform to their places, the other members piling at the front of the stage, Professor Kim taking his place as coach as the questions started.

For the most part Jungkook was silent, with the occasional clapping for his team. He didn't know much about what was going on, but spent some time explaining the things he knew to Jin, who looked completely clueless. At least his studying had paid off, to some extent. They both watched with anticipation as the scores slowly evolved into a tie, which meant that Taehyung would be coming up as the tiebreaker for the sudden deathmatch Q&A.

Jungkook watched Taehyung approach the center of the stage, shaking hands with the other Team Captain and readying their pens and papers. The coaches came up to the stage, Taehyung sharing a few words with Professor Kim. Taehyung looked so different now, Jungkook thought with a slight daze, so focused and serious, nodding along as the professor spoke to him.

Then Taehyung looked up, and their eyes met.

Brown eyes seemed to twinkle as it stared at his face, even with the distance between them. Slowly, Taehyung’s lips turned up, and Jungkook instantly blushed, thinking that his heart would finally give with how fast and hard it pounded. The older’s gaze shifted beside his face, and Taehyung smiled wider, seeing Jin waving at him, and tapped the professor's shoulder, nudging his head in their direction.

The professor turned around, and seeing his spouse on the stands with his student, also smiled, smaller, but still there. Both men apprised their significant others, with faces so suddenly similar that Jungkook was struck with a sense of déjà vu, Taehyung a younger version of the professor, with features that so resemble each other, now that they were both smiling.

Beside him Jin was smiling and waving back. "Come on, wave at them too," He said, nudging his shoulder lightly with his own. Flame faced, Jungkook shyly did as he said, raising an arms and giving a small wave towards the older, hoping that he would see it.

And later on, as Taehyung completely decimated his opponent and won the finals, Jungkook had to admit that yes, Taehyung  _did_  see him bright and clear.

The bleachers exploded into noise, Jungkook and Jin along with them as Seoul National University won and was finally declared the champions.

"Kookie! Jin-hyung!" Taehyung, still pumped up and exhilarated with their win, vaulted off the stage and made his way up to them, team jacket slung around his shoulders, sweat dripping from the tips of his hair and making his clothes stick to his body. In his disheveled, exhausted state Kim Taehyung still had the ability to make his knees feel weak. "You both made it!" And thus Jin was promptly ignored as Taehyung made a beeline for the younger teen, Jungkook not noticing the contemplative, searching look the older man was giving them.

"That was a great match, hyung." Jungkook said as a way of a greeting, smiling. Taehyung was as tall as Jin, Jungkook realized, and Jin was shorter than Professor Kim, maybe 2 centimeters shorter. "You played so well."

Taehyung smiled, this time looking so adorable that Jungkook had to stop the urge to ruffle his hair. "Thank you." He said, back to usual self, completely different from the domineering player he saw on the stage just moments ago. "We won! We're the champions!" He laughed, unable to stop himself, looking so happy and elated Jungkook didn't have the heart to stop him, also glad for his boyfriend.

"I'm happy for you," Jungkook answered sincerely, and stiffened as he was suddenly swept up into a tight embrace. Taehyung felt warmer than usual, smelling of sweat, musk and cinnamon, his cheek was already damp with moisture. Jungkook fell into it just the same, smiling a little and hugging the other back. It felt good, to be held like this, like they were the only people in the world. Jungkook didn't even have the capability to blush anymore with how many times he had in that day alone.

"It was because of you that I won. I didn't want to lose, not with you watching." The words were quietly said in his ear, and the Jungkook turned red at that admission, feeling flattered and embarrassed at the same time. "I'm really glad that you came by to watch. It means a lot."

"I-It's nothing. You didn't have to thank me." Jungkook quickly denied, fidgeting, tracing the crest on the other's jersey, curling his fingers into the material just the same. He leaned his cheek on Taehyung’s shoulder briefly, unable to resist. He teen was just so  _warm_. "I didn't have anything to do that's important, so…"

"Still. You came. And that's what matters." He was pulled away faster than he would've liked, but as Taehyung did the volume went up again, and Jungkook was painfully reminded that they were outside, and a lot of people were possibly watching them since, you know, he was  _hugging the person who won the tournament_. But Taehyung’s stare was captivating; with the way they sparkled and gleamed, brimming with happiness. And they only stood there closer than normal, staring at each other, Jungkook offering a tentative smile back.

It was only through Jin’s polite cough that Jungkook was brought back to the present.

"H-Hyung!" He jumped seemingly ten feet high and whipped his head towards the older man, who was looking at the both of them with some understanding and amusement. Shit, he completely forgot that Jin was still there, Jungkook thought with some despair. "U-um, t-this…!" He stammered, trying to find an explanation, an excuse, anything to deny what he saw, but the way other's lips curled up into a smile he knew anything he would say would be futile.

"So…" Jin started off pleasantly enough, making Jungkook freeze at the sound of his voice. But Jin wasn't looking at him, but at _Taehyung_ , whose face seemed to turn from red to pale white in a matter of seconds. "TaeTae, how long have you been…  _friends_  with Jungkook?" The way he said the words made the two of them flinch.

"… Jin-hyung, I can explain this." Taehyung edged forward, wrapping a hand around the Jungkook’s wrist and moving so he slightly shielded him. Jungkook didn't know what could have warranted such a reaction, but he didn't like it. Taehyung was nervous, tense, he could feel it with the way his hand trembled as it held his arm, and Jungkook would have blushed if not for the fact that the situation looked so serious.

"Hyung…" In a moment of impulse, Jungkook took the other’s hand instead, lacing their fingers together and squeezing it softly. It made Taehyung look at him, holding each other's gaze, and in one split second, everything was understood.

And then everything was broken when Jin started to laugh.

"Jin-hyung?" Taehyung looked incredulous, exchanging looks with the Jungkook, who felt as bewildered as the other felt. Jin continued to laugh at them, shaking his head, pressing fingers to his lips. He tried to stem his chuckles, staring fondly at the two of them.

"Please, don't look so worried, you two." Jin’s gaze softened and he placed a soothing hand on both of their shoulders. "I'm happy, Taehyung." He smiled gently. "That it's Jungkook. He's a very nice boy." He looked at Jungkook, who was startled with the depth of understanding in those eyes, of the empathy in them. "I would have chosen him too if I had the chance to."

"You're not… disappointed?" Taehyung hedged in a hesitant word, so stunned that he forgot to ask on just how they already knew his boyfriend. "I mean, if I'm, well, doesn't that mean that the family tree would—"

"Kim Taehyung, I'm the last person who would question your preferences." Jin pointed out with a quirk of his lips, giving him a look that made Taehyung flush in slight embarrassment. "Yes, I approve, and I'm happy for you. Now come here and give me a hug." He smiled slightly.

Taehyung hesitated just for another second before he was moving forward, quickly sweeping the older man into a hug, Jin returning it just as tightly, before looking at him critically.

"Thank you." Taehyung smiled at Jin, who also did the same. While to some outsiders it may look like a conversation between lovers, with how handsome both of them were, Jungkook could only feel a familial affection radiating between the two of them. "Jin-hyung, by the way, how did you know—?"

"Who Jungkook is? Kook-ah, you didn't tell him yet?" Jin moved his attention to him, and Jungkook shook his head quickly, cheeks once again becoming tinged with pink. He never told Taehyung anything about it, simply because he never asked. And he didn't know what Taehyung’s reaction would be like if he told him. "It hasn’t come up yet, Jin-hyung."

"Jin, Jungkook. Taehyung." The math professor suddenly materialized beside his spouse, and Jungkook almost had a heart attack. Thank god the older man never did that during his classes; otherwise he would've died of shock. Professor Kim was carrying two large bags, one of which he recognized as Taehyung’s. "Taehyung, don't leave your things behind." He scowled, and the younger teen gave a somewhat sheepish smile.

"My bad, hyung." He got his bag and slung it over his shoulder, and Professor Kim gave him another glare before turning to his spouse. "Jin, let's go?" He smiled slightly.

"Yes, let's." Jin chuckled, slipping their fingers together and looking at the younger couple. "Jungkook, if you don't mind, would you like to have dinner with us? We’ll celebrate Taehyung’s win, and I think we need to catch up on things." He said, cheerful and eyes twinkling, even as Jungkook looked at him in question. "You're welcome to join us, of course."

"I…" There was that look again, the please-accept-because-you-really-don't-have-a-choice look. "O-Of course, Jin-hyung. I'd be happy to." Jungkook managed to answer back, trying not to cringe, but ended up following them with a small sigh anyway. And as the older man tugged at the professor’s arm to move out, the two of them were left behind to trail after them.

"Kookie, I don't understand." Taehyung finally said, even as they got out of the building and started to walk towards the car park. "How do you know Jin-hyung? Have you met him before?" He was confused, rightly so, and Jungkook thought of how he should explain all of it.

"Well… I already slept in your house, once." The story was too long to tell at that moment, and he never, ever wanted to lie to Taehyung. The other was too precious, too important for him to hide the truth from. "I'll tell you everything when I get the chance to."

"… All right." Taehyung looked like he wanted to protest at first, but thought better of it. "Are you sure you want to have dinner with us? I could always tell them you're busy." His tone edged to concern, and with a bit of tension, and Jungkook shook his head, smiling a little.

"It's fine. I might as well meet them again, now.” _Officially._ “At least I know they approve of me." Jungkook watched the older couple just a ways in front of them, so affectionate and so clearly in love. Their worlds clearly revolved around each other and he could hardly believe that he was now experiencing the same thing. He glanced at Kim Taehyung, wonderful, patient, loving Taehyung, who was now looking at him and cocking his head in slight curiosity, smiling. "Hm?"

"Hyung." He was moving before he knew it, Jungkook was pulling Taehyung’s jacket down and pressing their lips together, right there in the walk path to the car park where there would be some people who could stare at them.

Jungkook’s face was still flushed, but he refused to break eye contact, chuckling a little when Taehyung continued to gape openly at him like a fish.

"Congratulations. For winning the tournament."

He was completely done for.

He was really in love with the professor's son.

**Author's Note:**

> THE SEQUEL IS HERE. I DIDN'T KNOW HOW I DID IT, BUT I DID IT. THE COMEBACK SLAYED ME. JFC BANGTAN IS NOT GOOD FOR MY HEALTH.
> 
> It's a shorter sequel, mostly because my brain isn't functioning correctly and my laptop is still broken. This was made in a couple of hours, because comebacks are awesome muses. 
> 
> My favorite track has to be Begin and Awake and... everything. Just everything. 
> 
> If you have more ideas for this series, hit me up at my [tumblr](https://equinoxsolstice.tumblr.com), or leave a comment below. NamJin is life. VKook is life.


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